An electronic device may include a display with pixels formed using light-emitting diodes, thin-film silicon transistors, thin-film semiconducting-oxide transistors, and capacitors. The silicon transistors, semiconducting-transistors, and capacitors may have control terminals that are coupled to gate or routing lines that extend across the face of the display and that are formed in a low resistance source-drain metal routing layer. Forming routing/gate lines using the low resistance source-drain metal routing layer dramatically reduces the resistance of the gate lines, which enables better timing margins for large display panels operating at higher refresh rates.